Automatic screw-down control for rolling mills



Sept. 17 1935; G. N. HUGHES AUTOMATIC SCREW-DOWN CONTROL FOR ROLLINGMILLS I 3 Sheets-Sheet 1 Filed Jan. 12, 1932 & Q Q @E 5/4/ 4? 6. MHug/46.5

ATTORNEYj G. N. HUGHES Sept. 17, 1935.

AUTOMATIC SCREW-DOWN CONTROL FOR ROLLING MILLS I Filed Jan. 12, 1952 3Shets-Sheet 2 v INVENTOR Sept. 17, 1935. a. N. HUGHES 2,014,475

I AUTOMATIC SCREW-DOWN CONTROL FOR ROLLING MILLS Filed Jan. 12, 1932 3Sheets-Sheet 3 m/ ZLSZ .2 4L52 51.52

INVENTOR Patented Sept. 17, 1935 UNITED STATES PATENT} OFFICE AUTOMATICSCREW-DOWN CONTROL FOR ROLLING MILLS of Ohio Application January 12,1932, Serial No. 586,223

5 Claims.

My invention relates to sheet metal rolling mills and is concerned withimprovements in screwdown mechanism for adjusting the mill rolls.

An object of my invention is to provide novel,

precise and eflicient means for actuating roll adjusting screws orscrew-downs so that sheets, bars, or sheet packs as they pass back andforth between the rolls will control automatically the quick andaccurate setting of the rolls 'so as to move the latter closer andcloser together until the cycle of rolling operations is completed,whereupon the rolls are reset to full open position so that the samecycle of operations, or any desired variation thereof, may be resumed.

It is a further object that the automatic control of the roll adjustingmeans shall be coordinated with the control, by the rolled stock, of theautomatic operation of the mechanical sheet catchers and feed tables tothe end that the operation of the mill as a whole shall be automaticallycontrolled by the rolled stock and a saving in labor and improvement instandardization of output obtained.

. Another object of my invention is to provide a screw-down mechanismadapted to exert its greatest force upon the rolls to set them inengagement with each other for the final pass of the stock. With theincreasing power available to thus set the rolls I attain an increasingaccuracy of adjustment which is of greatest importance as applied to thefinishing pass.

, A further object of my invention is to provide means adapted toprevent the breakage of parts of the screw-down mechanism when the rollsare brought into engagement with each other for the final pass of thestock through'the rolls.

A further object is to provide great flexibility and accuracy of rolladjustment by utilizing a reversible crank motion with transmissionelements designed to provide for a variable crank throw and a readychange total movement of the head screws, intermediate roll positionsbeing controlled by adjustable limit means to stop the crank for eachpass position.

Briefly my invention comprises a reversible motor acting throughsuitable speed reduction gearing to drive-a crank through a partialrotation which in turn acts through an adjustable driving rod, a lever,anda yielding connecting link to actuate the roll adjusting screws. Asthe stock passes through the rolls and onto the sheet catcher, it throwsa switch which starts the motor. The motor circuit is broken by passlimit switches adjustably mounted in position to be automaticallyactuated by an arm on the crank shaft and to regulate the draft onindividual passes. An electrically operated brake is wired in serieswith the motor circuit and acts to overcome quickly the momentum of therotor when the circuit is broken. A switch controlled by the 5 finaldischarge of therolled stock acts to reverse the arm and reset the limitswitches for the next complete cycle.

My invention further comprises the novel details of construction andarrangements of parts 10 which in their preferred embodiment only areillustrated in the accompanying drawings which form a part of thisspecification, and in which:

Fig. 1 is a plan viewof a mill and the screwdown mechanism;

Fig. 2 is a side elevational view of same;

Fig.3 is a sectional detail view of a safety coupling interposed in theconnecting link;

Fig. 4 is a detail section of the adjustable mounting. for a limitswitch; and 20 Fig. 5 is a wiring diagram illustrating the manner inwhich the screw-down mechanism is controlled.

Referring now to the drawings for a better understanding of my.invention, I show a mill 25 frame 6 providedwith bearings 1, 8 and 9, 1and 8 being mounted for vertical movement, and rolls ll, [2 and I3journaled in the bearings. The movement of the bearings I and 8'and thesetting of the rolls to regulatethe pass clearance, is 30 controlled byadjustment head screws l4 and 1'6 which are threaded through the upperportion of the frame for engagement with the bearings 1. The rolls aredriven in the direction indicated by the arrows by an electric motor(not shown). 35 After the screws, or screw-downs as they are commonlytermed, have been properly adjusted with respect to each other, they arecaused to move simultaneously by means of a tie bar I! which ispivotally connected at the ends of tie 40 bar arms l8 and IS. The armsare mounted on their respective screws by means of collars 2| and bolts22 and adapted to be engaged at their outer ends between the teeth 23formedin wheels 24 and 26 which are keyed to the screws. 5

The screw-downs are actuated by a reversible electricmotor 21 whichdrives a crank arm 28 mounted on a crank shaft 29 through a worm 3| andworm gear 32. A driving rod 33 is pivotally connected at its one end tothe crank arm, by 50 means of a journal bolt 34 which is mounted in aradial slot 36 in the crank arm and can be adjusted to vary the crankthrow. At its other end the rod. 33 is connected to a lever 31. Thelever 31 is pivotally connected at its lower end to a rigid 55 frame 38and at its upper end to a connecting rod 39 which in turn is connectedto a pivot arm 4I' mounted on the screw I4.

The pivot arm M is secured to a collar 42 mounted on the screw H by abolt 43 and is adapted to engage between the teeth 23 on the wheel 24 soas to rotate the screw when swung about its pivot. A pair of pins 44 areprovided on the outer end of the pivot arm for engagement in an eye 46formed on the end of the connecting rod 39, and thus I provide anadditional means to vary the throw of the crank as applied to thescrew-downs.

The connecting rod 39 is formed in two sections 41 and 48 yieldablyconnected by a safety coupling which is shown more clearly in Fig. 3 ofthe drawings. The end of the section 41 is enlarged and bored at 49 toreceive the end of the section 48 and is slotted at 5I to receive a pin52 secured in the section 48. The enlarged end of section 41 is threadedto receive a nut 53 which acts with a collar 54 to hold a spring 55under compression and to resist relative axial movement between thesections.

Referring now to Fig. 2, I show a portion of a feed table 51 and acatcher table 58 which are shown and described in a copendingapplication by A. G. Delany, filed on October 1st, 1931, Serial No.566,230, and are adapted to act with the herein described apparatus toperform the rolling operation automatically. The stock to be rolled iscarried on the feed table to the lower rolls and is received on thecatcher table which returns the stock to the feed table through theupper rolls or over them as may be desired.

The motor 21 has a shunt field 81 connected across the leads IM and I02hereinafter described.

The motor 21 is started by a flag switch I which is actuated by thestock at the completion of each pass of the stock through the rolls andthe motor is stopped by limit switches 82 which are opened by a controlarm 83 mounted on the crank shaft 28. After the stock has completed thepasses through the rolls, say by making five passes, the control armwill actuate a reversing switch 64 which sets the relay circuits so thatthe last operation of the flag switch I00 will reverse the motor andreturn the screw-down mechanism to its first position and reset thelimit switches for the next cycle of passes. The limit switches 62 and84 are adjustably mounted on a bracket 65a by means of bolts 8517 passedthrough circumferential slots 650 as will be seen in Fig. 4. Theseswitches are of standard toggle type and will remain in the position inwhich they are left by their control arm 63.

In setting up the screw-down mechanism, the screws I4 and I6 areadjusted to maintain the rolls parallel and are held in this adjustedposition at all times by the tie bar I1 and the arms I8 and I9. Thevertical movement of the screws is controlled by adjusting the journalbolt 34 along the slot 36 formed inv the crank arm 28 and also byselecting the inner or outer pin 44 provided on the pivot arm 4 I Theinitial vertical positions of the screws can be roughly adjusted byengaging the pivot arm 4I between different teeth 23 formed on the wheel24, and a fine adjustment can be obtained by shortening or lengtheningthe driving rod 33 by means of a turn-buckle 66. C

When rolling thin sheets of metal, the screwdowns are lowered to holdthe rolls tightly in engagement with each other so I have provided thesafety coupling in the connecting rod 39to prevent the possibility ofbreakage or distortion of parts. As shown in Fig. 3, the section 48 isadapted to slide farther into the socket 49 against spring resistancewhich can be adjusted by the nut 53.

The screw-down mechanism is automatically controlled for five passes ofthe stock as follows, reference being had to Fig. 5 in the drawings. Asthe stock is carried by the feed table 51 to the lower rolls, the screwsare in their raised or first position and are lowered to their secondposition when the flag switch I00 is actuated by the stock passing on tothe catcher table 58.

When the stock strikes flag switch I00 in making the first pass it opensswitch FS I closes switch FS2, and switch FS3 remains closed, therebyenergizing the set up relay E by closing a circuit through the leadsIOI, I05, switch FS2, lead II2, switch FS3, lead II3, relay E, lead II4,switch" U2 to lead I02. When the relay E closes, a holding circuit iscompleted through the leads IOI, I06, switch E3, lead II2, switch FS3,lead II3, relay E, lead I I4, switch U2 to lead I02.

As the stock passes farther onto the catching table it eventuallyreleases the flag switch I00 which is caused to resume its uprightposition by the springs H and to close switch FSI andopen switch FSZ.When switch FSI closes, a circuit is completed to the relay D throughleads IOI, I05,

switch FSI, lead H6, switch E2, lead II1, switch 2LSI, lead I I8, switch3L3 I, lead I I8, switch 4LSI, lead I2I, switch 5LSI, lead I22, relay D,lead I23, switch UI, to lead I02. When the relay D is thus energized itopens switch DI and closes switches D2, D3 and D4. A holding circuit isthen provided for the relay D through lead IOI, switch D2, lead I24,switch E2, lead II1, switch 2LSI, lead II8, switch 3LSI, lead II8,switch 4LSI, lead I2 I switch 5LSI,lead I22,relay D, lead I23, switchUI, to lead I02.

The closing of switch D3 and D4 complete a circuit to the motor 21through lead IOI, switch D4, lead I26, brake solenoid I21, lead I28,motor 21, lead I29, switch D3, to lead I02. The motor then acts to movethe screw-downs downwardly into position for the second pass of thestock through the rolls during which, the control arm 63 actuates #Ilimit switch to close switch ILSI and then actuates #2 limit switch toopen switch 21.81 and close switch 2LS2. When the switch 2LSI opens, thecircuit through relay D is broken causing the switches D3 and D4 tobreak the circuit leading to the motor 21 and to the brake solenoid I21.

When the motor circuit is broken the brake solenoid I21 is de-energizedpermitting a spring 12 to draw a brake shoe 13 mounted on a brake lever14 into engagement with a brake drum 10 secured on the motor shaft 11,thereby quickly overcoming the momentum of the motor armature andbringing the screw-downs accurately to predetermined position for thenext pass. The brake mechanism is mounted within a housing 18. Thescrew-down mechanism is now in its second position and the stock is fedfor its second pass from the catching table through the upper rolls andonto the feed table. As the stock leaves the catching table it movesthe-flag switch I00 to open the switches FSI and FS3, and switch FS2remaining open. When the switch FS3 opens, the circuit to the relay E isbroken, thereby closing the switch EI and opening the switches E2 andE3. After the stock leaves the catching table, the flag switch isrestored to its upright position by the springs II thereby closingswitches F8! and F83.

The switch FSI now closes a circuit leading to the relay D through leadsIOI, I05, switch FSI,"

lead II6, switch EI, lead I3I, switch 2LS2, lead II8, switch 3LSI, leadII9, switch flLSI, lead I2I, switch 5LSI, lead I22, relay D, lead I23,switch UI,'to lead I02. The relay D now acts to close the switches D3and D4 to complete the circuit to the motor 21 as described before.After the motor has lowered the screw-downs for the third pass, thecircuit leading to the relay D is broken by the control arm 63 actuatingthe #3 limit switch which opens the switch 3LSI and closes the switch3182. The de-energization of the relay D causes the switches D3 and D4to open and break themotor circuit.

As the stock passes onto the catching table after the third pass, itdepresses the flag switch I and completes a circuit to the relay E asdescribed in connecting with the first pass of the stock onto thecatching table. .The relay D is energized, when the stock has passed farenough onto the catching table to permit the flag switch to assume itsupright position, through the leads IOI, I05, switch FSI, lead IIB,switch E2, leads II! and I32, switch 3LS2, lead H9, switch 4LSI, leadI2I, switch '5LSI, lead I22, relay D, lead I23, switch UI, to lead I02.The relay D then .closes the switches D3 and Dlto complete the circuitto the motor which acts to lower the screw-downs for the fourth pass.The motor is stopped by the control arm 63 striking the limit switch#lLS which opens the switch sumes its upright position, the relay D isenergiged through the leads I 0| I05, switch FSI, lead II6, switch El,lead I3I, switch 2152, lead IIO, switch 4LS2, lead I2I, switch 51SI,lead I22, relay D, lead I23, switch UI, to lead I02. The relay nowcloses the switches D2, D3 and D4 and opens switch DI. The switches D3and D4 complete the circuit to the motor which lowers the screw-downsfor the fifth and final pass and is stopped by the control arm 63opening the switch 5LSI which breaks the'circuit to the relay D causingthe switches D3 and D4 to open.

After the stock has passed through the rolls for the fifth or finalpass, it depresses the flag switch I00, to complete a circuit to therelay E, and then passes over the catching table to a piling machine(not shown). When the flag switch I00 resumes its upright position, therelay U is energized through the leads I0 I, I05, switch FSI, lead II6,switch E2, leads II! and I32, switch 31-82, lead 9 switch 5LS2, leadI33, switch IISI, lead I33, relay U, lead I36, switch DI, to lead I02.-

The switches U4 and U5 complete a circuit in a reverse direction throughthe motor armature to move the screw-downs upwardly into their raisedposition. As the control arm 63 travels in the reverse direction itresets each of the limit switches 51S, ILS, 3LS, 218 and ILSsuccessively and causes the motor to stop when the #I limit switch opensthe switch ILSI and breaks the circuit to the relay U which in turnopens the switches U4 and U5 in the motor circuit.

3 The roll control mechanism is thus reset for a new cycle of passes andthe adjustment of the rolls for each pass can be regulated by theposition in which the limit switch for that pass is set in the bracket65a. Also by the adjustment of limit switch ILS the initial position ofthe screw-downs can be controlled. The extent of the full travel of thescrew-downs can be controlled by the adjustment of the throw of thecrank drive thereto in either or both ways I have provided for such anadjustment. The initial setting of the screw-downs can be controlled bythe turnbuckle or by shifting the toothed wheels after releasing themfrom their actuating mechanisms by lifting pivot arm ll. beindependently set by lifting the tie bar arms I8 and I 9. A greater orless number of passes may be provided for by using more or less limitswitches 62 which to distinguish them in Fig. 5 are marked ILS, 2LS etc.

The whole control mechanism for the rolls is automatic; it can be placedout of the way so as not to interfere with roll changes or repairs; it.will through the brake stop the motor so quickly as to insure definiteintermediate positions for pass control; and, due to the crank actingfor the setting of the final pass as it closely approaches dead centerposition, I obtain great power for the adjustment and unusual accuracyfor this most important pass as any given angular movement of the crankin this position imparts the least actuation to the mechanism foroperating the screw-downs.

While I have shown my invention in but one form, it will be obvious tothose skilled in the art that it is not so limited, but is susceptibleof various changesand modifications, without departing from the spiritthereof, and I desire, therefore, that only such limitations shall be.placed thereupon as are imposed by the prior art or as are specificallyset forth in the appended claims.

What I claim is:

1. In a rolling mill for rolling and re-rolling stock, said stock alwayspassing through a given pass in the same direction having rolls andadjusting head screws therefor, means to actuate the head screwscomprising a crank, a. reversible motor to oscillate the crank, atransmission between said motor and crank, a series of limit switches,an arm movable with the crank to trip said switches and reset them as itoscillates, circuits containing switches and relays which are controlledby each limit switch to stop the motor, and means for controlling saidcircuits responsive to the movement of the rolled stock to start themotor and to reverse it.

2. In a rolling mill for rolling and re-rolling stock having adjustinghead screws, driving means for the said head screws comprising areversible motor and a crank driven thereby, and an operative connectionwith the said head screws, a series of limit switches controlling aseries of electric circuits for starting, stopping and reversing thesaid motor, means integral with the said crank to actuate the said limitswitches, the

'said switches being bodily adjustable according to any predeterminedprogram.

justable throw crank driven by the prime mover,

Either screw-down may 15 a series of switches and associated electricalcircuits for stopping, and reversing the said prime mover, stockactuated means for starting the said prime mover, and means integralwith the said crank for actuating the said switches, the said switchesbeing bodily adjustable according to any predetermined program.

4. In a rolling mill for rolling and re-rolling stock, having adjustinghead screws, a reversible electric motor, a crank driven by the saidmotor, an operative transmission between the said crank and the saidscrews, stock actuated means to start the said motor, a series ofadjustable limit switches with associated circuits to stop and reversethe said motor, means integral with the said crank to "actuate the saidswitches tostop the motor at predetermined intervals of operation, thefinal switch in the said series operable to reverse the motor, and thesaid means resetting the said switches durlng the reverse operation ofthe motor.

5. In a rolling mill for rolling and re-rolling stock, a frame, rollsmounted on the frame for vertical movement, screws adapted to regulatethe pass between the rolls, a crank actuated link mechanism adapted toturn the screws to regulate the class clearance between the rolls aftereach pass of the stock, a motor to drive the said crank, saidcrank'actuated means being adapted to exert its maximum force in settingthe rolls for the final pass of the stock, automatic means controlled bythe stock being rolled for starting the crank actuated means to decreasethe clearance between the rolls, and limit switches adapted to stop theforward movement of the crank actuating means in predeterminedpositions, one of the limit switches being adapted to set up relays toreverse the direction of travel of the crank actuated means, responsiveto the final pass of the stock through the rolls to reset the screws fora new cycle of passes.

GUY NEWTON HUGHES.

